Hydroxylamine and hydroxylammonium salts are compounds which have a variety of applications. For instance, hydroxylammonium nitrate may be used as a component of liquid propellant and as a reducing agent in photographic operations. In some of these applications, it is desirable that a hydroxylammonium salt solution of high purity be available.
Hydroxylamine is useful as an intermediary in chemical processes especially in the pharmaceutical and agricultural industries. It is also useful in stripper formulations. Stripper formulations may be used to remove photoresists from or clean a substrate. For example, hydroxylamine stripper solutions are used to remove polyimide coatings from metal foils. Hydroxylamine stripper solutions are extensively utilized in the printed circuit board and semiconductor industries. Frequently, solutions of hydroxylamine, especially solutions prepared from hydroxylammonium salts, contain undesirable amounts of impurities such as salts, acids, metals and unwanted organic materials. Thus, there also exists a need for hydroxylamine solutions having high purity.
There exist several production methods to manufacture hydroxylamine and hydroxylammonium salts. Some of these methods, however, do not provide hydroxylamine solutions or hydroxylammonium salt solutions of high purity which some applications of the compounds require. Consequently, there remains a substantial demand for large quantities of high purity hydroxylamine solutions and hydroxylammonium salt solutions.